Part A: Making Sounds
a. How would you change the code to make the song play twice as fast?
Take every number in noteDurations and multiply it by two. Since the actual duration is 1000 divided by the number in the array, doubling the number will halve the duration.
b. What song is playing? ;-)
The Star Wars theme.
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Part B: Writing to the LCD
a. What voltage level do you need to power your display?
5V
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b. What was one mistake you made when wiring up the display? How did you fix it?
When I finished soldering the display, I wanted to test it by hooking it up to the power supply. Unfortunately, I connected power and ground in reverse, and the display didn't activate. I only realized my mistake later, when I was wiring up the rest of the display. I finished connecting it, and luckily the display still works.
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c. What line of code do you need to change to make it flash your name instead of "Hello World"?
The line that reads 'lcd.print("hello, world!");'. I need to change the string to "Akshay Srivatsan".
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Part C: Fancy Inputs
1. Potentiometer
a. Post a copy of your new code in your lab writeup.
int sensorPin = A0; // select the input pin for the potentiometer
int ledPin = 13; // select the pin for the LED
int sensorValue = 0; // variable to store the value coming from the sensor
void setup() {
// declare the ledPin as an OUTPUT:
pinMode(ledPin, OUTPUT);
}
void loop() {
sensorValue = analogRead(sensorPin);
analogWrite(ledPin, sensorValue/1024.0*255);
}
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2. Flex Sensor
a. What resistance do you see with a Multimeter when the sensor is flat? When it is bent?
Flat: 8.7 kOhm
Bent: 26.6 kOhm
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b. What kind of voltages should we expect for the Arduino analog pin based on the sensor resistance?
Flat: 2.5 V
Bent: 1.7 V
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c. How does the range of the LED's brightness change compared to the potentiometer?
It will no longer reach the "off" state (since there is a minimum resistance significantly greater than zero). The overall range will be smaller, since the flex sensor outputs a smaller range of voltages.
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d. Include a copy of your Lowly Multimeter code in your lab write-up.
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int sensorPin = A0; // select the input pin for the potentiometer
int ledPin = 13; // select the pin for the LED
int sensorValue = 0; // variable to store the value coming from the sensor
void setup() {
// declare the ledPin as an OUTPUT:
pinMode(ledPin, OUTPUT);
lcd.begin(16, 2);
}
void loop() {
sensorValue = analogRead(sensorPin);
analogWrite(ledPin, (sensorValue-300)/220.0*255); //I measured a range from ~310 to ~510. Scaling 300-500 to 0-255 should give me the full range of brightnesses.
lcd.clear();
lcd.print(sensorValue);
}
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a. What resistance values do you see from your force sensor?
26k Ohms to 0.8 kOhm (and infinite resistance when not pressed at all).
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b. What kind of relationship does the resistance have as a function of force applied? (e.g., linear?)
According to the Datasheet, there is an inverse relationship (R = 1/F).
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c. Include a copy of your FSR thumb wrestling code in your lab write-up.
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
/* Voltage Range of ~1.7 V to ~3.2 V */
int sensorPin1 = A0; // select the input pin for the potentiometer
int sensorPin2 = A1;
int ledPin = 13; // select the pin for the LED
int sensorValue1 = 0; // variable to store the value coming from the sensor
int sensorValue2 = 0;
void setup() {
// declare the ledPin as an OUTPUT:
pinMode(ledPin, OUTPUT);
lcd.begin(16, 2);
}
void loop() {
lcd.clear();
sensorValue1 = analogRead(sensorPin1);
sensorValue2 = analogRead(sensorPin2);
if (sensorValue1 == sensorValue2) {
lcd.write("Tie!");
}
else if (sensorValue1 > sensorValue2) {
lcd.write("Player 1 wins!");
}
else if (sensorValue1 < sensorValue2) {
lcd.write("Player 2 wins!");
}
delay(50);
}
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Video: